1. Field of the Invention
The present invention relates to an underwater vacuum. More particularly, the invention relates to an underwater vacuum specifically designed for removing bacterial film from large drinking water reservoirs.
2. Background and Description of the Related Art
Protection of the public's health requires that potable water supplies be free of microorganisms that can cause health effects in humans. Also, supplies of potable water must be free from other contaminants that may taint the water and/or negatively impact its acceptability by the consumer, i.e. the members of the public. To ensure consistent and acceptable water quality, rules and regulations regarding testing, maintenance, and maximum tolerable levels of contaminants for potable water reservoirs have been established. Disinfectant chemicals are used to destroy microorganisms in the water. However, it has been shown that sediment which characteristically accumulates at the bottom of potable water reservoirs insulates biological contaminants from the disinfection chemicals. Inspection of water storage tanks is recommended at least every five years. Many municipalities, which are charged with ensuring the quality of the water, opt to clean and inspect their reservoirs every year.
This annual cleaning and inspection has traditionally been done by first draining the reservoir and then having teams of men physically enter the reservoir to clean and inspect it. This approach has many drawbacks, and some examples of these drawbacks are listed below. First, the procedure is wasteful of natural resources and is very costly. Second, the draining and filling of the reservoir can disturb the sediment, releasing biological contaminants into the pipes in the water distribution area served by that reservoir. Third, draining and filling a reservoir causes mechanical stress to the structure of the reservoir, which can lead to cracks in the reservoir structure. Fourth, the men entering the reservoir with their tools can cause damage to the protective finish on the walls of the reservoir. Fifth, when a reservoir is drained there will usually not be an adequate supply of water to fight a major fire in the water distribution area served by the reservoir.
To avoid the aforementioned drawbacks, the underwater vacuum system of the present invention has been proposed. The underwater vacuum of the present is particularly adapted to ensure that the vacuum can remove sediment from the reservoir without causing turbidity in the water and thus avoiding the attendant introduction of biological contaminants into the water. The underwater vacuum of the present invention allows a team of divers to accomplish the cleaning of a potable water reservoir without the drawbacks associated with the periodic emptying and filling of the reservoir.
Although many underwater vacuum systems have been proposed in the art, none are seen to be specially adapted for the removal of sediment from potable water reservoirs while keeping any turbidity or biological contamination introduced into the water within the exacting requirements for potable water reservoirs.
The following patents and other documents illustrate some examples of underwater vacuums that have been proposed in the underwater vacuum art.
U.S. Pat. No. 3,795,027, issued to Albert W. Lindberg, Jr. on Mar. 5, 1974, and U.S. Pat. No. 4,498,206, issued to Heinz W. Braukmann on Feb. 12, 1985, show underwater vacuums having fixed brush bristles for cleaning swimming pools.
U.S. Pat. No. 5,404,607, issued to Pavel Sebor on Apr. 11, 1995, shows a self-propelled underwater vacuum for cleaning swimming pools. The Sebor device uses one or more pivotally mounted oscillators, that are caused to oscillate by the flow of water through the vacuum, to cause the vacuum to move in a random path along the bottom of the swimming pool.
U.S. Pat. No. 5,412,826, issued to Dennis A. Raubenheimer on May 9, 1995, shows a self-propelled underwater vacuum for cleaning swimming pools. The Raubenheimer device uses a turbine driven by the flow of water through the suction cleaner to power a pair of wheels that propel the vacuum.
U.S. Pat. No. 5,617,600, issued to Ercole Frattini on Apr. 8, 1997, shows a self-propelled underwater vacuum for cleaning swimming pools. The Frattini device uses a submersible electric motor to drive a pump impeller to create suction and to drive a set of rollers to propel the underwater vacuum.
United Kingdom Complete Patent Specification Number 1,092,133, By Russell Edward Winn, published on Nov. 22, 1967, shows an underwater vacuum for cleaning the hulls of ships or inside storage tanks. The Winn device is a self propelled vacuum with a steerable wheel and a pump for creating suction. The Winn device also has two rotating brushes that rotate about axes perpendicular to the surface being cleaned. The Winn device is not concerned with the introduction of contaminants into the surrounding water column.
European Patent Application Number 468,876, By Michael John Chandler et al., published on Jan. 29, 1992, shows a self-propelled underwater vacuum which uses a turbine to power the drive wheels of the vacuum. The device of chandler et al. has fixed brush bristles.
None of the above inventions and patents, taken either singularly or in combination, is seen to describe the instant invention as claimed. In particular, none of the above inventions and patents disclose a turbine powered brush having an axis of rotation parallel to the surface being cleaned and/or the unique structure of the suction head of the present invention which allows vacuuming sediment without introducing turbidity, and the attendant biological contaminants, into potable water supplies.